INVESTIGADORES
PAUTASSI Ricardo Marcos
congresos y reuniones científicas
Título:
Ethanol-induced locomotor activity in rats: age-related differences and association with ethanol-induced reinforcement
Autor/es:
PAUTASSI RM
Lugar:
Sapporo
Reunión:
Congreso; 2012 International Society for Biomedical Research on Alcoholism (ISBRA) World Congress; 2012
Institución organizadora:
Science Council of Japan
Resumen:
Ethanol-induced locomotor activity (LMA) has been proposed as a proxy for ethanol-mediated appetitive reinforcement. In mice, ethanol typically induces stimulatory and
depressant motor effects at low (< 2.0 g/kg, Faria et al, 2008) and high doses (>2.0 g/
kg; Quoilin, Didone, Tirelli & Quertemont, 2010), respectively. Mice studies also indicated
an inverse relationship between age and sensitivity to ethanol-induced LMA. Quoilin
et al. (2010) found significantly greater ethanol-induced LMA in early adolescent mice
than in late adolescents or in adult mice, whereas adults exhibited greater sensitivity
to ethanol?s sedative effects. Rats, on the other hand, have been considered as being
mostly insensitive to ethanol-induced motor stimulation. In a recent study, however, we
found reliable ethanol-induced LMA in adolescent rats given high-dose ethanol (i.e., 2.5
g/kg) through the intragastric route and tested in a large open-field arena during the
rising limb of the blood ethanol curve (post-administration minutes 5-12). We employed
this paradigm to test age-related differences in ethanol-induced LMA. Contrary to our
expectations, adolescent and adult rats did not differ in their susceptibility to ethanol-induced LMA. Subsequent experiments analyzed, in adolescent rats, the association
between ethanol-induced LMA and ethanol-induced reinforcement. Specifically, ethanol-induced conditioned place preference and conditioned taste aversion (CPP and CTA) were
conducted in animals previously screened for ethanol-induced LMA. Based on previous
theories (e.g., Wise & Bozarth, 1987; Robison and Berridge, 2008) and studies (Arias,
Molina, Spear, 2009), we expected that ethanol-induced LMA would be negatively and
positively associated with CTA and CPP scores, respectively. The adolescents exhibited
ethanol-induced CPP and CTA, yet these measures of ethanol reinforcement were not
associated with ethanol-induced LMA. Overall, the results suggest that rats are sensitive
to ethanol-induced LMA, particularly when testing focuses on the early phase of the toxic
process, when blood ethanol levels are rising. The results, however, do not support an
association between ethanol-induced LMA and conventional measures of ethanol-induced
reinforcement.